Brush and brush-holder for magneto-electric machines.



PATENTED SEPT. 13, 1904.

E. B. VJAOOBSON, BRUSH AND BRUSH HOLDER FOR MAGNETO ELECTRIC MACHINES.

APPLICATION ILED AUG.Z0.1903.

N0 MODEL.

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1T0. 770,175. Patented September 13. 1904:.

UNITED STATES PATENT OFFICE.

EDWARD B. JACOBSON, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO THE PITTSFIELD SPARK COIL COMPANY, OF PITTSFIELD, MASSACHU- SETTS, A CORPORATION OF MASSACHUSETTS.

BRUSH AND BRUSH-HOLDER FOR lVlAGNETO-ELECTRIC MACHINES- SPECIFICATION forming part of Letters Patent N0. 770,175, dated September 13, 1904.

Application filed August 20, 1903. Serial No. 170,167- (No model.)

To all whom it y cmwflni taining the said core, and a shell 83, ofbrass.

Be it known that I, EDWARD B. JACOBSON, a The employment of the wire-gauze core in- 5 citizen of the United States, residing at Pittssures perfect contact with the commutator,

field, in the countyof Berkshire, State of Masthe graphite serving to lubricate the contactsachusetts, have invented a certain new and ing surface of the commutator, while the brass useful Improvement in Brushes and Brushshell protects the graphite and holds the lat- Holders for Magneto-Electric Machines, of ter in compact form and also insures perfect which the following is a specification, referelectrical contact between the brush and the once being had therein to the accompanying brush-holder. The presser-arm 11, which co- Io drawings. operates with each brush 8, is supported by The invention consists more particularly in a pivotal stud 111 and is acted upon by a brushes and brush-holders for magneto-elecspring 112, the free extremity of which lat- 6o tric machines. ter bears against a projection 113 on the outer Various special aims or objects of diiferent side of the presser-arm, the said spring tend- 15 features of the invention are indicated in the ing to move the presser-arm in a direction to course of the following description. press the corresponding brush radially inward Ihave shown in the accompanying drawings against the periphery of the commutator.

the invention in the best form of embodiment For the purpose of enabling the tension of which I have thus far devised. the spring 112 of each presser-arm to be ad- 20 In the drawings, Figure 1 is a partlysecjusted so as to vary as desired the force with tional elevation of one end of a dynamo havwhich the brush is pushed into contact with ing my invention applied thereto. Fig. 2 is the commutator a hub 11 1, having upon its a view in section along the line 22 of Fig. 1. outer end a flange 115 and a circular series of Fig. 3 is a partly-sectional view illustrating projections 116, is fitted upon the correspond- 25 the manner of mounting the brush-holders ing stud 111 with capacity to turn thereon.

9 9. Fig. 1 shows in plan, partly broken The presser-arm 11 is sleeved upon the exteaway and in vertical cross-section, one of the rior of this hub, so as to turn freely thereon.

brushes. Withina hole in the outer end of the stud Having reference to the drawings, 1 desig- 111 is fixed a pin 117, the opposite ends of 30 nates part of the casing of adynamo; 1, one the said pin projecting on opposite sides of of the field-coils; 3, the armature; 6, the comthe said stud and being adapted to enter bemutator, and 7 the shaft on which the armatween adjacentprojections of the series of proture and commutator are mounted. jections 116. The hub is chambered at its in- 8 8 are the commutator-brushes. The said ner side to receive an expanding spiral spring 3 5 brushes are contained in tubular cylindrical 118, which is compressed between the interior brush-holders 9 9, which latter are mounted shoulder of the hub and the adjacent collar in fixed position upon the transverse web 10, or washer 119 next the fixed support of the 8 5 forming part of the casing. The brushes are stud, the said spring acting with a tendency to pressed against the surface of the commutator hold the said hub pressed outwardly upon the 4 by means of spring-actuated presser-arms 11 stud, with certain of the projections 116 in en- 11, which latter act to take up the wear of the gagement with the pin 117. A coil or spiral brushes. One of the brushes is shown sepaforming portion of the spring 112 encircles rately in plan, partly broken away and in the hub 11 1 between the flange 115 and the vertical crosssection, in Fig. 4 of the drawarm 11, and the corresponding end of the 45 ings. It comprises, essentially,acentral core, spring is engaged with the hub. It will be as 81, of fine wire-gauze wound spirally into perceived that the hub constitutes a support a cylindrical coil, a cylindrical body or penfor the coil portion of the spring and an oil 82, of pressed or tempered graphite, conabutment from which the spring reacts in pressing against the projection 113 of the presser-arm 11. The engagement of the pin 117 with the projections 116 of the hub prevents the hub from turning under the influence of the tension of the spring. If, however, it is desired to adjust the said tension, this may be accomplished by pressing the hub inwardly along the stud 111, so as to compress the spring 118, and far enough to disengage the projections 116 from the pin 117, and then turning the hub in either direction as may be required in order to increase or diminish the tension to the required degree, after which on relieving the lateral pressure against the hub and permitting the spring 118 to press it outwardly again the projections 116 thereof will reengage with the pin 117, carried by the stud 111, and lock the hub in its position of adjustment.

The free extremity of each presser-arm 11 works within vertical slots 91 91, which are formed through the upper and lower sides. of the corresponding brush-holder. By the walls of the said slots the presser-arm is held in proper position and guided in its movements. By contact with the periphery of the commutator the inner or working end of the brush becomes worn in concave shape, fitting the said periphery, thereby furnishing the largest contact-surface and diminishing the resistance and consequent sparking. For the purpose of preventing the brush from turning within the brush-holder, so that its concave face will no longer fit fully against the commutator, which would diminish the extent of the surface-making contact with the commutator, the outer end of the brushis notched or slotted, as at 8 1, for a short portion of its length, and within the notch or slot is received the presserarm. The engagement of the presser-arm with the sides or walls of the said notch or slot holds the brush from turning. For the purpose of enabling the brush to be removed from the brush-holder a longitudinal slot 92 is formed in the outer side of the brush-holder. Through this slot the point of a suitable tool may be inserted into engagement with the brush, and by movement of the said tool inward along the slot the brush may be pushed radially inward out of the brush-holder.

The brush-holders and also the presser-arms are insulated from the web 10 in manner which I will presently describe. In order to obviate necessity for causing the current to flow from the brush through the presser-arm itself and also through the spring 112, which actuates such arm, the stud 111, on which the presser-arm is mounted, is itself placed in direct electrical communication with the adjacent brush-holder through the medium of a plate 12, to which the brush-holder and the said stud are applied and with which they are in electrical contact. The plate 12 itself is insulated from the web 10 by means of asheet 121, Fig. 2, of vulcanized fiber or other suitable material, the fastenings by which the parts are united together being suitably insulated from the web 10. The inner end of the stud 111is extended through a transverse hole in the Web 10, and this hole is hushed with insulating material, as also shown in Fig. 2. The said inner end of the stud is screw-threaded and receives a nut 13, which is insulated from the web by a suitable washer, as shown. Were the spring 112 included in the circuit, it would tend to become heated during the operation of the dynamo, and the result of the heating would be to destroy its temper, rendering it useless or inefficient.

While I have been particular to describe the invention in the best form of embodiment which I have thus far devised, it is of course evident that various modifications in construction, arrangement, &c., may be made within the spirit of my invention.

From the respective studs 111 111 wires 14:

'14 extend within the casing to and connecting with the bindingposts 15 15, which latter project from the exterior of the said casing. To the said binding-posts in practice are connected the main conducting-wires.

I claim as my invention 1. The improved commutator-brush, comprising, essentially, the core of wire-gauze wound into spiral form, the body or pencil of graphite, and the inclosing metal shell, substantially as described.

2. The combination with the commutator,

the brush, and the brush-holder,of the presser- I arm, the spring for actuating the said presserarm, the adjustable hub having the series of projections on the outer end thereof, thepivotal stud, and the locking-pin on said stud engaging with the said projections to lock the hub in the desired position of adjustment.

3. The combination with the commutator, the brush, and the brush-holder, of the presserarm, the spring for actuating the said presserarm, the adjustable hub, the spring acting to press the said hub transversely, the pivotal stud, and the locking-pin on said stud engaging with the said hub to lock the same in the desired position of adjustment, substantially as described.

4:. The combination with the commutator, the brush,and the brush-holder, of the presserarm, its actuating-spring, and the pivotal mounting for the said arm, of an insulated support in common for the said brush-holder and pivotal mounting serving to connect the two electrically and extraneously of the said spring, substantially as described.

5. The combination with the brush having the slotted end, of the brush-holder having the slotted wall or shell, the presser-arm working in the slot of the said wall or shell and guided thereby, and also entering the slot of the brush to prevent the brush from turning, and means for operating the said presser-arm, substantially as described.

6. The combination With the brush having slot of the brush to prevent the latter from the slotted end, of the presser-arm entering turning, and means for operating the said the slot to prevent the brush from turning, presser-arm, substantially as described.

and means for operating the said presser-arrn, In testimony whereof I affix my signature in 5 substantially as described. presence of two Witnesses.

7. The combination With the brush having 7 r w T the slotted end, of the brush-holder having ARD JALOBSOD" the slotted Wall or shell, the resser-arm \Vitnesses: Working in the slot of the said Wall or shell CHAS. F. RANDALL,

IO and guided thereby, and also entering the VILLIAM A. COPELAND. 

